Southington, Conn.-based Thomas Products Ltd.’s Model 2100 is constructed with polysulfone (an FDA approved material). It’s an in-line flow switch used for detecting insufficient flow rates in liquids. One feature is the incorporation of a low flow orifice and adapter assembly, which makes the flow switch capable of set points as low as 1 cc/min. in water. Without this assembly, the unit can yield high set points up to 1.5 gpm. This unit can withstand pressure at 250 psig at 70 degreesF and temperatures up to 225 degrees F.